BitBlt'ing one DC into another

[adzzzz]

OK here's the score, I've created two device contexts and loaded a bitmap using the LoadImage API. I'm now 'selecting' the bitmap into the first DC and the BitBlt'ing it into the second DC but when I try to BitBlt this DC to the form for testing I get nothing.

This is the troublesome code:

'Create a copy of the original bitmap so it can be masked
  Dim hbmCopy As Long, hdcCopy As Long
  
  hDC = CreateCompatibleDC(0)
  hdcCopy = CreateCompatibleDC(0)
    
  hbmCopy = CreateCompatibleBitmap(0, 16, 16)
  
  'Select the original image
  SelectObject hDC, m_hbmMain
  'SelectObject hdcCopy, hbmCopy
 
  'BitBlt the original into the copy DC
  Debug.Print "copying from ", hDC, "to", hdcCopy
  Debug.Print "result:", BitBlt(hdcCopy, 0, 0, 16, 16, hDC, 0, 0, vbSrcCopy)
 
  'See if we can BitBlt our copied one onto the form
  Debug.Print "bitblt onto form", BitBlt(Me.hDC, 16, 0, 16, 16, hdcCopy, 0, 0, vbSrcCopy)
  
  'Refresh the form
  Me.Refresh
  
  DeleteObject hbmCopy
  DeleteDC hdcCopy
  DeleteDC hDC

I'll also attach the form incase anyone needs a closer inspection. When the command button is clicked 2 images of an apple should appear in the top-left corner.

Cheers for any help, adehh.